The public has always proved curiously resistant to backing vocalists who attempt to take the spotlight for themselves. For every Luther Vandross, who began his career behind David Bowie, there are 100 Doris Troys, who is doomed to be known not for her own records, but as the wailing woman on Pink Floyd's dreadful Great Gig in the Sky.
So the news that Martina Topley Bird's debut solo single, Need One, failed to trouble the charts has a depressing familiarity about it. Topley Bird spent the mid-1990s as Tricky's vocal foil: indeed, Tricky's records have never really seemed right since their partnership dissolved in 1998. As tonight's concert proves, however, writing off Topley Bird would be a hopeless oversight.
British music is not exactly drowning in distinctive female talent at the moment. Topley Bird is certainly that. Her voice is defiantly individual: torpid and bluesy, yet somehow very English and pretty. It fits her music. Her forthcoming album, Quixotic, comes thick with guest appearances - Tricky, producer David Holmes, arranger David Arnold, even Californian metallers Queens of the Stone Age - but live, the songs are stripped back. What emerges is a spooky, disjointed sound, driven not by beats but by harmonica and acoustic guitar. The tempo rarely rises above a languorous slink, but the mood darts about wildly: murky, threatening and discordant one moment, muzzy and sensual the next.
There is much rattling of odd-looking percussion instruments, evoking an anglicised take on both Dr John's voodoo-obsessed soul and the Nina Simone of African Mailman. These are lofty influences; without charisma, the result could sound like wan pastiche, and charisma is not something former backing vocalists are noted for. Topley Bird barely speaks, but she exudes a heavy-lidded, slightly menacing stage presence. Tonight, at least, she is impossible to ignore.